Is there any advisory board in TeX world?
W3C is an association of companies where any company that pays the membership fee can join. It also allows individual "invited experts" from non-member companies to work on standard (W3C Recommendation) documents. (I have such a role in the Math Working group responsible for MathML). The HTML working group has a rather different model of non-member contribution, where essentially anyone can gain invited status on the working group.
W3C doesn't have any official regulatory role. Its standards are followed or not depending if they are perceived as being useful. It has no power of enforcement.
So the nearest equivalent organisation for TeX is the TeX User Group. That does not try to organise any standard activities, it does however provide some infrastructure to help develop those standards such as email lists (notably for pdftex) and helping to manage monetary contributions to development work.